Vessels are commonly treated to reduce or eliminate narrowings caused by arteriosclerotic disease. Interventional treatments can include use of balloon angioplasty, stenting, thrombectomy, atherectomy, and other procedures. During treatment particulate debris can be generated at the treatment site. Infarcts, strokes, and other major or minor adverse events are caused when debris embolizes into vasculature from the treatment site.
To prevent embolization of debris, embolic protection devices have been developed. During a procedure such devices can be placed in a length of vessel, commonly referred to as a landing zone, distal or proximal to the treatment site. Embolic protection devices can remove emboli from the bloodstream by filtering debris from blood, by occluding blood flow followed by aspiration of debris, or can cause blood flow reversal to effect removal of debris. The shape, length and other characteristics of an embolic protection device are typically chosen based on the anatomical characteristics in the vicinity of the treatment site. However, some anatomies present specific challenges due to the anatomical shape or configuration.
Some anatomies have little or no room for deployment of an embolic protection device near to a treatment site. For example, lesions in the distal portion of a coronary artery bypass graft have short lengths of graft distal to the lesion, and the native vessel distal to the graft anastomotic site is often too small in diameter for satisfactory deployment of a distal embolic protection device. Further, coronary artery bypass grafts can have extensive diffuse disease and suitable landing zones of comparatively healthy conduit can be very short. In yet another example, vessels that branch immediately distal to a treatment site, such as renal arteries, have very short landing zones in the short common vessel distal segment. In another example, easily damaged structures, such as the petrous segment of the internal carotid artery, can be located distal to an intended treatment site, and an embolic protection device with a long landing zone can damage these structures.
Some devices have long filtering and/or wire tip structures and these structures contribute to the overall landing zone length of the device. If the filtering portion of the device is reduced in length the capacity of the filter for debris capture and recovery can be reduced. Some devices have wire structures that are attached to a filtering or occlusive structure in a way that allows treatment devices, such as balloon angioplasty catheters, to deflect the embolic protection device away from the wall of the vessel being treated, thereby allowing embolic debris to bypass the embolic protection device.
Some known embolic protection devices have landing zones ranging from 5 to 12 cm in length, and due to these long lengths these devices cannot protect a number of anatomical sites from embolic debris released by treatment devices.
What is needed are embolic protection devices having short landing zones, that are not deflected by treatment devices, and that have adequate debris capture and recovery capacity.